A system for automatically detecting side edge arc control in an electroslag process

Abstract

The utility model discloses an automatic detection electric slag process occurs side arc control system, including PLC controller (1), high voltage circuit breaker (2), current transformer (3) and voltage transformer (4), high voltage circuit breaker (2) and current transformer (3) all with the smelting power circuit (5) of electric slag furnace series connection, voltage transformer (4) is parallel with the smelting power circuit (5) of electric slag furnace, and high voltage circuit breaker (2), current transformer (3) and voltage transformer (4) all are connected PLC controller (1), be connected with alarm (6) on the PLC controller (1), high voltage circuit breaker (2), current transformer (3) and voltage transformer (4) all are through the shielded cable connection PLC controller (1). The utility model has can improve electric slag furnace production security's advantage.

Description

Technical Field

[0001] This utility model belongs to the field of electroslag furnaces, and in particular relates to an automatic detection system for side arc control during the electroslag process. Background Technology

[0002] Existing electroslag furnaces, such as Figure 2 As shown, the system includes a bottom water tank, above which are arranged a crystallizer and a fume hood. Electrodes are located inside the crystallizer, and dummy electrodes extend from the upper ends of the electrodes into the crystallizer and fume hood. An exhaust pipe is installed on the fume hood. The working principle is as follows: slag is fed into the crystallizer, and the current output from one end of the power supply returns to the other end of the power supply via the electrodes, slag, and bottom water tank, forming a smelting circuit. The slag is first melted to form a slag pool, where a large amount of heat is generated to melt the electrodes. The bottom of the electrodes is melted layer by layer by the heat from the slag pool and drips to the bottom of the crystallizer to solidify into an electroslag ingot.

[0003] Side arcing events may occur during the electroslag remelting process in electroslag furnaces. These events can be caused by factors such as large electrode welding curvature leading to misalignment, partial welding cracking during electrode melting leading to electrode misalignment, or misalignment of the electrode during movement when the gap between the electrode and the crystallizer is small. If the electrode touches the crystallizer during melting, it can lead to electrode arcing, crystallizer melting and damage, or even explosion, endangering production safety. Utility Model Content

[0004] The purpose of this invention is to provide an automatic detection and control system for side arcing during the electroslag remelting process. This invention has the advantage of improving the safety of electroslag furnace production.

[0005] The technical solution of this utility model is as follows: an automatic detection and control system for side arcing during electroslag remelting includes a PLC controller, a high-voltage circuit breaker, a current transformer, and a voltage transformer. The high-voltage circuit breaker and the current transformer are connected in series with the smelting power supply circuit of the electroslag furnace, and the voltage transformer is connected in parallel with the smelting power supply circuit of the electroslag furnace. The high-voltage circuit breaker, the current transformer, and the voltage transformer are all connected to the PLC controller.

[0006] In the aforementioned automatic detection system for side arcing during electroslag remelting, an alarm is connected to the PLC controller.

[0007] In the aforementioned automatic detection system for side arcing during electroslag processing, the high-voltage circuit breaker, current transformer, and voltage transformer are all connected to the PLC controller via shielded cables.

[0008] Compared with existing technologies, this invention adds a current transformer, a voltage transformer, and a high-voltage circuit breaker to the smelting power circuit of the existing electroslag furnace. The current transformer detects current changes in the smelting power circuit, and the voltage transformer detects voltage changes, transmitting the signals to the PLC controller. When the current change reaches a certain amplitude and persists for a certain period, or the voltage change reaches a certain amplitude and persists for a certain period, the PLC controller disconnects the smelting power circuit through the high-voltage circuit breaker, stopping smelting and issuing a warning through an alarm, allowing operators to take timely action and improving production safety. Therefore, this invention has the advantage of improving the production safety of electroslag furnaces. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the structure of this utility model.

[0010] Figure 2 This is a schematic diagram of the working principle of an electroslag furnace.

[0011] The labels in the attached diagram are: 1-PLC controller, 2-high voltage circuit breaker, 3-current transformer, 4-voltage transformer, 5-smelting power supply circuit, 6-alarm. Detailed Implementation

[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0013] Example: An automatic detection and control system for side arcing during electroslag remelting, such as... Figure 1 As shown, the system includes a PLC controller 1, a high-voltage circuit breaker 2, a current transformer 3, and a voltage transformer 4. The high-voltage circuit breaker 2 and the current transformer 3 are connected in series with the smelting power supply circuit 5 of the electroslag furnace, while the voltage transformer 4 is connected in parallel with the smelting power supply circuit 5 of the electroslag furnace. The high-voltage circuit breaker 2, the current transformer 3, and the voltage transformer 4 are all connected to the PLC controller 1 via shielded cables. An audible and visual alarm 6 is connected to the PLC controller 1.

[0014] When an electroslag furnace is working, it generates an alternating electromagnetic field through thousands or even tens of thousands of amperes of alternating current, which can interfere with signals. Using shielded cables can reduce signal interference.

[0015] Current transformer 3 is connected to the analog input module of PLC controller 1 to collect the actual current of smelting energized circuit 5 in real time. Voltage sensor 4 is connected to another analog input module of PLC controller 1 to collect the actual voltage of smelting energized circuit 5 in real time. The coil control terminal of high-voltage circuit breaker 2 is connected to the relay output terminal of PLC controller 1.

[0016] There are two alarm devices, one installed at the smelting site and the other installed on the control cabinet of the electroslag furnace.

[0017] The model of PLC controller 1 can be Siemens CPU1511-1PN.

[0018] Method 1: Step 1: Preset parameters.

[0019] Key parameters—current and voltage—can be preset via the touchscreen on PLC controller 1. These can be entered manually or automatically generated. The error between the current setting and the remelting process current setting is ≤100A; the error between the voltage setting and the remelting process voltage setting is ≤5V.

[0020] Step 2: Real-time monitoring – data collection and duration statistics.

[0021] Data Acquisition: After the smelting is started, the current transformer 3 and voltage transformer 4 continuously collect the actual values ​​and transmit them to the PLC controller 1 in real time (data is updated once every 10ms).

[0022] Difference judgment: PLC controller 1 calculates the absolute value of "actual value - set value" of current and voltage in real time. If any difference exceeds the allowable range (e.g., difference 1500A > 1000A), the built-in timer is immediately triggered to start timing; if the difference returns to the range within a certain time (e.g., 10s), the timer is cleared and reset.

[0023] Step 3: Logic execution – alarm and high voltage cut-off.

[0024] PLC Controller 1: PLC synchronously compares "difference status" with "duration data": if "difference exceeds the range and duration ≥ 10s", immediately execute dual actions, even if high-voltage circuit breaker 2 is disconnected and alarm 6 is activated.

[0025] During normal remelting, the actual values ​​of current and voltage will fluctuate normally around the set values, without continuously exceeding or falling below them. When a side arc occurs, the resistance decreases due to the short-circuit effect, causing the actual current to continuously exceed the set current, while the actual voltage continuously falls below the set voltage, and both lose their normal fluctuation state. Based on this characteristic, the following conditions can be used to determine this: If the actual current is consistently greater than the set current (a positive current difference exists) and the duration exceeds the set threshold (e.g., 10 seconds); or if the actual voltage is consistently less than the set voltage (a negative voltage difference exists) and the duration exceeds the set threshold (e.g., 10 seconds), either condition is considered a side arc. A dual current and voltage detection mechanism ensures reliable detection and avoids missed detections even under extreme parameter settings (e.g., when the current is set to an extreme value, voltage can be used for judgment, and when the voltage is set to an extreme value, current can be used for judgment).

[0026] As a preferred option, the following execution feedback functions are also available: Alarm: Triggers the audible and visual alarm (red light flashing + 80dB alarm sound), and a forced pop-up window appears on the touchscreen (displaying the over-limit parameters and duration). High-voltage cut-off: PLC controller 1 outputs a signal to the coil of high-voltage circuit breaker 2, and completes the tripping within 50ms, cutting off the high-voltage power supply to the smelting equipment and stopping smelting; Data recording: PLC controller 1 automatically stores out-of-limit events (time, actual value, baseline value, duration) to an SD card and retains them for 1 year for easy traceability and analysis.

[0027] Step 4: Troubleshooting and Recovery. After the operator has investigated and addressed the cause of the over-limit issue (such as electrode misalignment or power grid anomaly), they can reset the "high-voltage cut-off" status via the PLC touchscreen, reset the parameters, and restart the smelting process. The system automatically clears the over-limit timing data and restores real-time monitoring mode.

[0028] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

Claims

1. An automatic detection and control system for side arcing during electroslag remelting, characterized in that: The system includes a PLC controller (1), a high-voltage circuit breaker (2), a current transformer (3), and a voltage transformer (4). The high-voltage circuit breaker (2) and the current transformer (3) are connected in series with the smelting power supply circuit (5) of the electroslag furnace, and the voltage transformer (4) is connected in parallel with the smelting power supply circuit (5) of the electroslag furnace. The high-voltage circuit breaker (2), the current transformer (3), and the voltage transformer (4) are all connected to the PLC controller (1).

2. The automatic detection system for side arc control during electroslag remelting according to claim 1, characterized in that: An alarm (6) is connected to the PLC controller (1).

3. The automatic detection system for side arc control during electroslag remelting according to claim 1, characterized in that: The high-voltage circuit breaker (2), current transformer (3) and voltage transformer (4) are all connected to the PLC controller (1) via shielded cables.

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